1. Field of the Invention
The present invention relates to a system for backing up setting data of a plurality of circuit packages and, more specifically, to a backup method and system in a control system having a detachable backup memory.
2. Description of the Related Art
In general, a transmission apparatus in a switching system has a number of circuit packages (built-in circuit boards) which are detachably mounted on the backboard of the apparatus frame. This type of transmission apparatus further has a file package including a backup memory which stores start-up setting data such as a line connections state and a soft strap setting state of the transmission apparatus. When a communication service of the switching system is stopped due to, for instance, power shutoff, the communication service can be restored in a short time by using the start-up setting data stored in the backup memory.
FIG. 1 is a schematic block diagram showing a conventional control system having such a file package. A control package 10, a host supervisory/controlling apparatus (i.e., a central control apparatus) 20, a plurality of circuit packages 30 to be set, and a file package 40 are connected to each other via a backboard. Each of the circuit packages 10, 30 and 40 are detachably mounted by means of a connector. The control package 10 includes a processor 11 for controlling the circuit packages 30, an parallel I/O interface 12 for data communication with external systems, and interfaces for data communication with the host supervisory/controlling apparatus 20 and the packages 30 to be set. The file package 40 includes a backup memory 41 for storing start-up setting data, a battery 42 for supplying power to the backup memory 41, and a mode setting switch 43 that indicates whether there has occurred replacement work on the file package 40.
In the transmission apparatus having the above configuration, an operation of replacing a faulty circuit package with a new one or the same circuit package in another transmission apparatus is performed manually. In such an operation, there occurs no problem in replacing the control package 10 or the package 30 to be set. However, since the file package 40 stores data to be set in the associated transmission apparatus, a file package that has already been used in another transmission apparatus cannot be used for replacement as it is.
Therefore, a certain availability checking means is needed which allows the processor 11 of the control package 10 to recognize whether the start-up setting data stored in the file package 40 is available. In the above conventional apparatus, the mode setting switch 43 is provided as an availability checking means and a switching operation therefor is performed manually. More specifically, in restarting the apparatus, the processor 11 of the control package 10 checks the state of the mode setting switch 43. If the mode setting switch 43 is on, the processor 11 judges that the file package 40 is a substituted one. Thus, the processor 11 initializes the backup memory 41, starts up the apparatus, and stores start-up setting data of the respective packages into the backup memory 41. Upon completion of the restart of the apparatus, an operator switches the mode setting switch 43 to the off state. On the other hand, if the mode setting switch 43 is off in restarting the apparatus, the processor 11 judges that the file package 40 is not a substituted one. Thus, the processor 11 reads the start-up setting data from the backup memory 41, and restarts the apparatus.
A description will be made of another general availability checking means. First, in mounting the control package 10 and the file package 40, a particular pattern that was determined when the transmission apparatus was designed is stored into the backup memory 41. When the apparatus is restored from a power shutoff state, the processor 11 reads a pattern from the backup memory 41, and judges availability of the data stored in the backup memory 41 based on whether the readout pattern is the preset particular pattern.
However, in the conventional system in which the mode setting switch 43 is operated manually, it cannot be checked whether the start-up setting data stored in the backup memory 41 is available. Further, an operator is required to be present until completion of restarting. Since there are many packages to be set, it is very difficult to improve the working efficiency. Further, it is virtually impossible to be free of careless mistakes.
While the availability checking method using the particular pattern can check whether the file package 40 is the same one, it cannot check the start-up setting data of the backup memory 41 is available. This is so because even if the file package 40 is the same, a possibility is not denied that during power shutoff the file package 40 was used in another transmission apparatus and the data was written.
As described above, in the conventional system, it cannot be checked whether the start-up setting data stored in the backup memory was changed while the system was stopped. Therefore, for instance, when the power is shut off for maintenance and inspection, or the like, it is not completely assured that the same start-up setting data is stored. In particular, if a transmission apparatus in a switching system is restarted with start-up setting data of another transmission apparatus, a wrong connection state is established in the transmission apparatus concerned, causing too large influences on society. Therefore, there exists a problem that the apparatus cannot be restarted automatically when it is restored from a power shutoff state, for instance.
An object of the present invention is to provide a control system which can positively judge whether data stored in a backup memory is the same as the previous data, when the apparatus is restarted.
Another object of the invention is to provide a method and system which can automatically restart an apparatus having a backup memory.
A further object of the invention is to provide a circuit package including a backup memory in which, when the apparatus is restarted, a control package can positively judge whether data stored in the backup memory is the same as the previous data.
A backup memory package according to the present invention is detachably connected to a control system by means of a connection board. The control system is comprised a plurality of circuit packages detachably connected to the connection board, each circuit package requiring start-up setting data for start-up operation. The backup memory package is comprised of a battery for supplying power to the backup memory package through a power line and a backup memory for storing the start-up setting data.
The backup memory package is further provided with a battery monitor, a connection/disconnection member, and a flag memory. The monitor checks a voltage of a monitor input terminal at all times and generates a reset signal when the voltage of the monitor input terminal becomes lower than a predetermined reference voltage. The connection/disconnection member connects the monitor input terminal to the power line when the backup memory package is connected to the connection board, and disconnects the monitor input terminal from the power line when the backup memory package is removed from the connection board. The flag memory stores one of a set state and a reset state, and changes in state from the set state to the reset state when the reset signal is received from the monitor.
The control package controls the circuit packages and the backup memory package through the connection board, and determines whether the start-up setting data stored in the backup memory is valid or not, by checking the flag state of the flag memory, set or reset.
More specifically, the connection/disconnection member comprises a first connector and a second connector. The first connector is provided in the backup memory package, having a plurality of conductors for electrically connecting the backup memory package to the connection board. Two conductors thereof are connected to the power line and the monitor input terminal, respectively. The second connector is provided in the connection board detachably connected to the first connector. The second connector has a plurality of conductors corresponding to those of the first connector, two conductors thereof corresponding to the two conductors of the first connector are connected to each other, forming a return wire.
The monitor monitors a voltage of the battery through the power line and the connection/disconnection member when the backup memory package is connected to the connection board. The monitor outputs the reset signal to the flag memory when the backup memory package is removed from the connection board or when a voltage of the battery becomes lower than the predetermined reference voltage. The predetermined reference voltage is preferably set higher than a minimum voltage that assures holding of data stored in the backup memory and the flag memory.